The diurnal and seasonal behavior of long-term (approximately 20 months) 1.54 GHz amplitude scintillation measurements under low sunspot conditions observed at Huancayo, Peru are presented. The measurements refer to a low elevation geometry in the E-W plane at the magnetic equator. The data show clear equinoctial maxima of occurrence and confinement to the pre-midnight hours. There is a total absence of scintillations during the May--July period. The present results are critically compared to previously reported GHz measurements in the context of geometry of observations, equatorial irregularity strength variation and spatial structure information obtained from in-situ data.